Under Pressure
SciCast film goes here
If you're reading this text, try visiting http://scicast.org.uk/films/2008/01/under-pressure.html directly. If you're already there you probably need to update Flash
Under Pressure
St. Paul's Girls' School
Download film (right-click)Demonstration , Explanation , Physics , Secondary
Through crushing a can we explain why the air does not crush us.
Director's Notes:
Physics demonstrations don’t come much more classic than the ‘crumpling can,’ and there’s nothing wrong with that.
Water is boiled in a drinks can, which is then (carefully!) inverted into cold water. As the steam condenses the external air pressure forces the sides of the can inwards. Simple.
SciCast Notes:
Believe it or not, this is the first ‘crushing can’ we’ve had on SciCast — we’re delighted to finally have a record of this old classic demonstration.
A very nicely-made film, straight and to the point, with a good clear voice-over and some carefully chosen shots. Good job.
One thought, though — “pounds per square inch”? Really? I’m no longer a spring chicken, sadly, but even I’ve never worked in psi except when pumping up my bike tyres. What’s wrong with SI units?
— Jonathan